It was dubbed by organisers as "all about meat, smoke, summer and good times" but, for many at the Sydney Barbecue Festival, the only roasted flesh they saw was their own, as thousands queued for hours in sweltering heat only to be told food had sold out.

He said vendors and organisers were fully aware of expected crowd numbers but were swamped about lunchtime as crowds arrived early to beat the afternoon thunderstorms.

"Early in the morning, [the demand] hit the guys at once. There were a range of things working against us and we were playing catch-up.

"We actually had fewer people come than we briefed our traders on."

Mr Vitale said food stalls that sold out were restocked later in the day.

Adam Leung, who endured the long wait for food, described the festival as "the worst value for money from any event I've been to".

"My wife got very badly sunburned waiting at a table in the sun for me while I waited two hours for food. She didn't want to leave the table to give it up (we had no idea how long we'd be waiting for food)," he wrote on the event's Facebook page on Sunday morning.

"[In] summary between two of us it was $70 for entry, $10 parking, $18 for drinks from the bar, $40 for 2 serves of wings and 2 soft drinks .. basically $138 for a small lunch, a couple of drinks and bad sunburn.

"Honestly I feel really ripped off by that," he wrote, but added that he planned to give the festival another chance next year.

Your event was unbelievably terrible. We had a group of 9 of us that were so excited for this event, planning to stay...